What is GIS? - An introduction. (Last I checked - 091506 - this site was having problems. If it still is, please send a message to me at email@example.com and let me know. Thank you.)
The GIS Primer.
Global Positioning System Overview.
Accessing Spatial Data Tutorial.
Many GIS Related Tutorials from the University of Michigan.
USGS - Geographic Information Systems Tutorial.
IDRISI Resource Center Salzburg Homepage.
GIS pages available for self-study and reference.
GIS and the Geographer's Craft.
Free Digital Maps
Free GIS maps from MapCruzin.com.
Free Census 2000 map layers from Proximity One.
ESRI's free Census Tiger 2000 shapefile map layers.
Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD 2006). You might also order the same data on a free CD set here. (As of 091506 the above was still available, but recently many things have been removed from this website. If you can no longer find this data, please email me at firstname.lastname@example.org and I will make our archived copies of this data available to you.)
National Atlas Map Layers Warehouse.
Interior Columbia Basin Ecosystem Management Project spatial data.
National GAP Analysis Program.
Casil - California Spatial Information Library.
FCC Wireless Antenna shapefiles.
CalTrans GIS Library.
FreeGIS.org Geo Data.
Simle world map with country attributes.
Digital Chart of the World.
Other Useful Resources
Odden's Bookmarks - 1000's of cartographic links.
GIS, GPS and related software.
OGC (Open GIS Consortium) Web Services.
6,800+ Chemical Profiles.
RTK Net chemical pollution databases.
U.S. Census American FactFinder.
U.S. EPA Envirofacts.
U.S. EPA Integrated Urban Air Toxics Strategy.
U.S. EPA National-Scale Air Toxics Assessment.
U.S. EPA Risk-Screening Environmental Indicators.
U.S. EPA Sector Facility Indexing Project.
U.S. EPA Toxic Release Inventory (TRI).
CDC - GIS and Public Health.
National Library for the Environment.
BLM Land and Mineral Records.
Terraserver satellite images.
FCC Wireless Telecommunications Bureau's Universal Licensing System (ULS) radio services downloadable zip files.
FCC Wireless Antenna Lookup.